TreeLayout (yFiles-for-JavaFX-Complete-3.0 API)

java.lang.Object
- com.yworks.yfiles.layout.MultiStageLayout
- - com.yworks.yfiles.layout.tree.TreeLayout

All Implemented Interfaces:

ILayoutAlgorithm
```
public class TreeLayout
extends MultiStageLayout
```
This layout algorithm arranges graphs with a tree structure.

Layout Style
TreeLayout provides multiple different arrangements of trees and subtrees. It is easy to customize the order of edges, the port assignment and the arrangement of the nodes for each subtree.

Tree layout algorithms are commonly applied to visualize relational data and produce diagrams of high quality that are able to reveal possible hierarchic properties of the graph. More precisely, they find applications in dataflow analysis, software engineering, bioinformatics and business administration.

Example graph with a layout calculated by TreeLayout using default settings Tree layout using different INodePlacers and rotations
Concept

The layout algorithm starts from the leaves and continues with their parents, then with the parents of the parents and so on. When a node is processed, the algorithm will use the corresponding INodePlacer instance to move its children (along with their subtrees) to a suitable position and to route the outgoing edges of this node. Then, the next local root node will be processed.

To avoid moving all nodes several times and to know the area that the subtrees occupy, the layout algorithm uses TreeLayout.SubtreeShapes. These TreeLayout.SubtreeShapes are moved and merged during layout calculation.

Features

Each subtree can have a different style of node placement. INodePlacers are responsible for arranging subtrees and their common root node. They can be specified separately for each local root with a IDataProvider registered with the graph using key NODE_PLACER_DPKEY.

A custom node can be defined as root of the tree using a IDataProvider registered with the graph with key SELECTED_ROOT_DPKEY.

The layout algorithm can be configured to reserve space for node labels and place the edge labels along edges such that the labels won't overlap with other graph elements. Edge labels are placed according to the information stored in a PreferredPlacementDescriptor instance. However, the placement along the edge will only affect the order of multiple labels at the same edge. The algorithm will always place the labels close to the target node.

Grouping of nodes can also be handled by this layout algorithm. It is important that a group node contains a whole subtree. Otherwise, the group nodes may overlap with each other or with other nodes. Furthermore, the user may specify minimum size constraints for each group node using IDataProvider key GroupingKeys.MINIMUM_NODE_SIZE_DPKEY.

TreeLayout supports custom sorting of the outgoing edges of a node. For example, a INodePlacer instance that implements IFromSketchNodePlacer provides a comparator that keeps the current order of siblings, allowing to extend the graph incrementally.

This layout algorithm can only handle graphs with a tree structure. To apply it to a general graph, a TreeReductionStage can be appended. This stage will temporarily remove some edges of the input graph until a tree is obtained. After the layout calculation, the stage will reinsert the edges that were removed and route them separately.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class TreeLayout.SubtreeShape
A TreeLayout.SubtreeShape represents the position and the borders of a subtree.

Nested Classes
Modifier and Type	Class and Description
`static class`	`TreeLayout.SubtreeShape` A `TreeLayout.SubtreeShape` represents the position and the borders of a subtree.

Field Summary

Fields
Modifier and Type	Field and Description
`static EdgeDpKey<Integer>`	`CRITICAL_EDGE_DPKEY` A `DataProvider` key for defining the priority of critical edges.
`protected LayoutGraph`	`graph` The input graph for which a layout is calculated.
`static NodeDpKey<MultiParentDescriptor>`	`MULTI_PARENT_DESCRIPTOR_DPKEY` A `DataProvider` key for retrieving descriptors for nodes in multi-parent structures.
`static NodeDpKey<INodePlacer>`	`NODE_PLACER_DPKEY` A `DataProvider` key for specifying a child node placer for each node.
`static NodeDpKey<Comparator<Object>>`	`OUT_EDGE_COMPARATOR_DPKEY` A `DataProvider` key for specifying the comparator for the outgoing edges.
`static NodeDpKey<IPortAssignment>`	`PORT_ASSIGNMENT_DPKEY` A `DataProvider` key for assigning ports to nodes.
`static NodeDpKey<Boolean>`	`SELECTED_ROOT_DPKEY` A `DataProvider` key for marking the node that will be used as root node of the tree.

Constructor Summary

Constructors
Constructor and Description

TreeLayout()
Creates a new TreeLayout instance with default settings.

Constructors
Constructor and Description
`TreeLayout()` Creates a new `TreeLayout` instance with default settings.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`applyLayoutCore(LayoutGraph graph)` Arranges the given graph as a tree.
`protected TreeLayout.SubtreeShape`	`createNodeShape(Node node)` Creates a `TreeLayout.SubtreeShape` for the given node that consists only of the bounds of this particular node.
`protected EdgeList`	`directTree()` Returns a list of edges that need to be reversed in order to obtain a valid rooted and directed tree from the input graph.
`INodePlacer`	`getDefaultLeafPlacer()` Gets the default `INodePlacer` instance that places the leaf nodes of the tree.
`INodePlacer`	`getDefaultNodePlacer()` Gets the default `INodePlacer` instance that arranges all subtrees that do not have a specific `INodePlacer` assigned using a `IDataProvider`.
`Comparator<Object>`	`getDefaultOutEdgeComparator()` Gets the default `Comparator` instance that sorts the outgoing edges in all subtrees that do not have a specific `Comparator` assigned using a `IDataProvider`.
`IPortAssignment`	`getDefaultPortAssignment()` Gets the default `IPortAssignment` instance for all subtrees that do not have a specific `IPortAssignment` assigned using a `IDataProvider`.
`protected INodePlacer`	`getNodePlacer(Node localRoot)` Returns the `INodePlacer` instance that is used for the placement of the local root node and the `TreeLayout.SubtreeShape`s.
`protected Comparator<Object>`	`getOutEdgeComparer(Node localRoot)` Returns the `Comparator` instance that will sort the outgoing edges connecting to the given node.
`protected IPortAssignment`	`getPortAssignment(Node localRoot)` Returns the `IPortAssignment` instance that places the ports of the connecting edges of the given node.
`protected Node[]`	`getRootsArray(Node root)` Returns an array of the nodes that will be laid out.
`protected IDataAcceptor`	`getSourceGroupDataAcceptor()` Gets a `IDataAcceptor` that can be used for temporarily overwriting the source group information used during the layout.
`protected IDataAcceptor`	`getSourcePortConstraintDataAcceptor()` Gets a `IDataAcceptor` that can overwrite the source `port contraint` temporarily used during the layout.
`protected TreeLayout.SubtreeShape`	`getSubtreeShape(Node localRoot)` Provides access to the `TreeLayout.SubtreeShape` for the given node.
`protected IDataAcceptor`	`getTargetGroupDataAcceptor()` Gets a `IDataAcceptor` that can be used for temporarily overwriting the target group information used during the layout.
`protected IDataAcceptor`	`getTargetPortConstraintDataAcceptor()` Gets a `IDataAcceptor` that can overwrite the target `port contraint` temporarily used during the layout.
`boolean`	`isGroupingSupportEnabled()` Gets whether or not group nodes are handled by the layout algorithm.
`boolean`	`isIntegratedEdgeLabelingEnabled()` Gets whether or not edge labels are placed by the layout algorithm.
`boolean`	`isMultiParentAllowed()` Gets whether or not multi-parent structures are allowed for this tree layout.
`boolean`	`isNodeLabelConsiderationEnabled()` Gets whether or not the layout algorithm reserves space for node labels.
`protected TreeLayout.SubtreeShape`	`layoutRoot(Node localRoot)` Calculates the layout for the given root node and its subtrees.
`protected void`	`reverseEdges(EdgeList reversedEdges)` Reverses the direction of given edges.
`void`	`setComponentLayoutEnabled(boolean value)` Sets whether or not the `ILayoutStage` used for arranging the components of the graph is activated.
`void`	`setDefaultLeafPlacer(INodePlacer value)` Sets the default `INodePlacer` instance that places the leaf nodes of the tree.
`void`	`setDefaultNodePlacer(INodePlacer value)` Sets the default `INodePlacer` instance that arranges all subtrees that do not have a specific `INodePlacer` assigned using a `IDataProvider`.
`void`	`setDefaultOutEdgeComparator(Comparator<Object> value)` Sets the default `Comparator` instance that sorts the outgoing edges in all subtrees that do not have a specific `Comparator` assigned using a `IDataProvider`.
`void`	`setDefaultPortAssignment(IPortAssignment value)` Sets the default `IPortAssignment` instance for all subtrees that do not have a specific `IPortAssignment` assigned using a `IDataProvider`.
`void`	`setGroupingSupportEnabled(boolean value)` Sets whether or not group nodes are handled by the layout algorithm.
`void`	`setIntegratedEdgeLabelingEnabled(boolean value)` Sets whether or not edge labels are placed by the layout algorithm.
`void`	`setMultiParentAllowed(boolean value)` Sets whether or not multi-parent structures are allowed for this tree layout.
`void`	`setNodeLabelConsiderationEnabled(boolean value)` Sets whether or not the layout algorithm reserves space for node labels.
`void`	`setParallelEdgeRouterEnabled(boolean value)` Sets whether or not the `ILayoutStage` used for routing parallel edges is activated.
`void`	`setSelfLoopRouterEnabled(boolean value)` Sets whether or not the `ILayoutStage` used for routing self-loops is activated.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - CRITICAL_EDGE_DPKEY
```
public static final EdgeDpKey<Integer> CRITICAL_EDGE_DPKEY
```
    A DataProvider key for defining the priority of critical edges.
    The layout algorithm tries to align each node pair that is connected by a critical edge (integer value > 0). This feature can, for example, be used for highlighting different edge paths that are important for a user. Conflicts between different critical edges are always resolved in favor of the higher priority.
    
    Critical edges will always align the centers of source and target node, thus replacing the current root alignment of the INodePlacer.
    
    The critical edge may not be straight if subtrees are rotated or port constraints are assigned.
    
    This feature is only supported by the following INodePlacers:
  - graph
```
protected LayoutGraph graph
```
    The input graph for which a layout is calculated.
  - MULTI_PARENT_DESCRIPTOR_DPKEY
```
public static final NodeDpKey<MultiParentDescriptor> MULTI_PARENT_DESCRIPTOR_DPKEY
```
    A DataProvider key for retrieving descriptors for nodes in multi-parent structures.
    The returned descriptor affects the layout of the multi-parent structure.
    
    This key is only considered if multi-parent structures are allowed, see MultiParentAllowed. Furthermore, all nodes that belong to the same multi-parent structure should return the same descriptor.
    
    See Also:
    
    setMultiParentAllowed(boolean)
  - NODE_PLACER_DPKEY
```
public static final NodeDpKey<INodePlacer> NODE_PLACER_DPKEY
```
    A DataProvider key for specifying a child node placer for each node.
    
    See Also:
    
    setDefaultNodePlacer(INodePlacer)
  - OUT_EDGE_COMPARATOR_DPKEY
```
public static final NodeDpKey<Comparator<Object>> OUT_EDGE_COMPARATOR_DPKEY
```
    A DataProvider key for specifying the comparator for the outgoing edges.
    
    See Also:
    
    setDefaultOutEdgeComparator(Comparator)
  - PORT_ASSIGNMENT_DPKEY
```
public static final NodeDpKey<IPortAssignment> PORT_ASSIGNMENT_DPKEY
```
    A DataProvider key for assigning ports to nodes.
    
    See Also:
    
    setDefaultPortAssignment(IPortAssignment)
  - SELECTED_ROOT_DPKEY
```
public static final NodeDpKey<Boolean> SELECTED_ROOT_DPKEY
```
    A DataProvider key for marking the node that will be used as root node of the tree.
- Constructor Detail
  - TreeLayout
```
public TreeLayout()
```
    Creates a new TreeLayout instance with default settings.
- Method Detail
  - applyLayoutCore
```
public void applyLayoutCore(LayoutGraph graph)
```
    Arranges the given graph as a tree.
    
    Specified by:
    
    applyLayoutCore in class MultiStageLayout
    
    Parameters:
    
    graph - the input graph
  - createNodeShape
```
protected TreeLayout.SubtreeShape createNodeShape(Node node)
```
    Creates a TreeLayout.SubtreeShape for the given node that consists only of the bounds of this particular node.
    It may also include node labels or NodeHalos.
    
    This method may be overridden to return a custom TreeLayout.SubtreeShape for the given node.
    
    Parameters:
    
    node - the given node
    
    Returns:
    
    a TreeLayout.SubtreeShape instance
  - directTree
```
protected EdgeList directTree()
```
    Returns a list of edges that need to be reversed in order to obtain a valid rooted and directed tree from the input graph.
    The root node of the tree is either a node marked by a IDataProvider registered with the graph with key SELECTED_ROOT_DPKEY or is defined according to Trees.getRoot(Graph).
    
    This method is called initially to calculate a rooted tree from the input graph. It may be overridden to apply a custom algorithm that determines which edges need to be reversed.
    
    Returns:
    
    a list of edges that need to be reversed
    
    See Also:
    
    reverseEdges(EdgeList)
  - getDefaultLeafPlacer
```
public INodePlacer getDefaultLeafPlacer()
```
    Gets the default INodePlacer instance that places the leaf nodes of the tree.
    
    Throws:
    
    IllegalArgumentException - if the default INodePlacer is set to null
    
    Default Value:
    The default value is LeafNodePlacer
    
    Returns:
    
    the default INodePlacer instance
    
    See Also:
    
    setDefaultNodePlacer(INodePlacer), setDefaultLeafPlacer(INodePlacer)
  - getDefaultNodePlacer
```
public INodePlacer getDefaultNodePlacer()
```
    Gets the default INodePlacer instance that arranges all subtrees that do not have a specific INodePlacer assigned using a IDataProvider.
    
    Throws:
    
    IllegalArgumentException - if the default INodePlacer is set to null
    
    Default Value:
    The default value is DefaultNodePlacer
    
    Returns:
    
    the default INodePlacer instance
    
    See Also:
    
    NODE_PLACER_DPKEY, setDefaultNodePlacer(INodePlacer)
  - getDefaultOutEdgeComparator
```
public Comparator<Object> getDefaultOutEdgeComparator()
```
    Gets the default Comparator instance that sorts the outgoing edges in all subtrees that do not have a specific Comparator assigned using a IDataProvider.
    
    When a Comparator for outgoing edges is null, the order of the edges will be maintained.
    
    Default Value:
    The default value is null. No sorting is executed.
    
    Returns:
    
    the new default instance or null if no specific sorting should be done
    
    See Also:
    
    OUT_EDGE_COMPARATOR_DPKEY, setDefaultOutEdgeComparator(Comparator)
  - getDefaultPortAssignment
```
public IPortAssignment getDefaultPortAssignment()
```
    Gets the default IPortAssignment instance for all subtrees that do not have a specific IPortAssignment assigned using a IDataProvider.
    
    Throws:
    
    IllegalArgumentException - if the default IPortAssignment is set to null
    
    Default Value:
    The default value is DefaultPortAssignment
    
    Returns:
    
    the default IPortAssignment instance
    
    See Also:
    
    PORT_ASSIGNMENT_DPKEY, setDefaultPortAssignment(IPortAssignment)
  - getNodePlacer
```
protected INodePlacer getNodePlacer(Node localRoot)
```
    Returns the INodePlacer instance that is used for the placement of the local root node and the TreeLayout.SubtreeShapes.
    The method may be overridden to return custom INodePlacer instances. It is possible to return a shared instance for multiple different nodes because the instances are not used after subsequent calls to this method.
    
    The current implementation returns the INodePlacer defined by the IDataProvider registered with key NODE_PLACER_DPKEY. It falls back to the default INodePlacer if there is no specific INodePlacer for the given node.
    
    Parameters:
    
    localRoot - the root of the local subtree
    
    Returns:
    
    the INodePlacer instance that places the subtree below the given local root node
    
    See Also:
    
    NODE_PLACER_DPKEY, getDefaultNodePlacer()
  - getOutEdgeComparer
```
protected Comparator<Object> getOutEdgeComparer(Node localRoot)
```
    Returns the Comparator instance that will sort the outgoing edges connecting to the given node.
    The Comparator can be null in case the initial edge order shall be used.
    
    The method may be overridden to return custom Comparator instances. It is possible to return a shared instance for multiple different nodes because the instances are not used after subsequent calls to this method.
    
    The current implementation returns the Comparator defined in the IDataProvider registered with key OUT_EDGE_COMPARATOR_DPKEY. It falls back to the default Comparator if there is no specific Comparator for the given node.
    
    Parameters:
    
    localRoot - the root of the local subtree
    
    Returns:
    
    the Comparator or null that sorts the outgoing edges of the given node
    
    See Also:
    
    OUT_EDGE_COMPARATOR_DPKEY, getDefaultOutEdgeComparator()
  - getPortAssignment
```
protected IPortAssignment getPortAssignment(Node localRoot)
```
    Returns the IPortAssignment instance that places the ports of the connecting edges of the given node.
    The method may be overridden to return customized IPortAssignment instances. It is possible to return a shared instance for multiple different nodes because the instances are not used after subsequent calls to this method.
    
    The current implementation returns the IPortAssignment defined by the IDataProvider registered with key OUT_EDGE_COMPARATOR_DPKEY. It falls back to the default IPortAssignment if there is no specific IPortAssignment for the given node.
    
    Parameters:
    
    localRoot - the root of the local subtree
    
    Returns:
    
    the IPortAssignment instance that assigns the ports of the edges at the given node
    
    See Also:
    
    PORT_ASSIGNMENT_DPKEY, getDefaultPortAssignment()
  - getRootsArray
```
protected Node[] getRootsArray(Node root)
```
    Returns an array of the nodes that will be laid out.
    The given node will be considered as the root of the tree. The order of the elements ensures that no parent is processed before one of its successors.
    
    This method may be overridden to change the order in which the nodes (and their subtrees) are handled. However, it is important to keep the parents after the successors. Only siblings can change places.
    
    Parameters:
    
    root - the node to be considered as root of the tree
    
    Returns:
    
    an array of nodes that will be laid out
  - getSourceGroupDataAcceptor
```
protected IDataAcceptor getSourceGroupDataAcceptor()
```
    Gets a IDataAcceptor that can be used for temporarily overwriting the source group information used during the layout.
    This method may be overridden to handle those edge groups separately.
    
    Returns:
    
    a IDataAcceptor to associate source edge groups with Edges
    
    See Also:
    
    PortConstraintKeys.SOURCE_GROUP_ID_DPKEY
  - getSourcePortConstraintDataAcceptor
```
protected IDataAcceptor getSourcePortConstraintDataAcceptor()
```
    Gets a IDataAcceptor that can overwrite the source port contraint temporarily used during the layout.
    This method sets temporary source PortConstraints, e.g., after edge reversal. It may be overridden to handle those PortConstraints separately.
    
    Returns:
    
    a IDataAcceptor to associate source PortConstraints with Edges
    
    See Also:
    
    PortConstraintKeys.SOURCE_PORT_CONSTRAINT_DPKEY
  - getSubtreeShape
```
protected TreeLayout.SubtreeShape getSubtreeShape(Node localRoot)
```
    Provides access to the TreeLayout.SubtreeShape for the given node.
    The TreeLayout.SubtreeShape contains information about the current extent and location of the subtree rooted at the node. It should only be modified during the layout of the parent node. Also, it won't be initialized before the layout of the corresponding subtree is calculated.
    
    This method updates the TreeLayout.SubtreeShape in layoutRoot(Node).
    
    Parameters:
    
    localRoot - the root of the subtree
    
    Returns:
    
    the TreeLayout.SubtreeShape instance if it has already been calculated, null otherwise
  - getTargetGroupDataAcceptor
```
protected IDataAcceptor getTargetGroupDataAcceptor()
```
    Gets a IDataAcceptor that can be used for temporarily overwriting the target group information used during the layout.
    This method may be overridden to handle those edge groups separately.
    
    Returns:
    
    a IDataAcceptor to associate target edge groups with Edges
    
    See Also:
    
    PortConstraintKeys.TARGET_GROUP_ID_DPKEY
  - getTargetPortConstraintDataAcceptor
```
protected IDataAcceptor getTargetPortConstraintDataAcceptor()
```
    Gets a IDataAcceptor that can overwrite the target port contraint temporarily used during the layout.
    This method sets temporary target PortConstraints, e.g., after edge reversal. It may be overridden to handle those PortConstraints separately.
    
    Returns:
    
    a IDataAcceptor to associate target PortConstraints with Edges
    
    See Also:
    
    PortConstraintKeys.TARGET_PORT_CONSTRAINT_DPKEY
  - isGroupingSupportEnabled
```
public boolean isGroupingSupportEnabled()
```
    Gets whether or not group nodes are handled by the layout algorithm.
    
    If this option is disabled, group nodes will be temporarily hidden and reinserted to enclose their content. This may lead to node overlaps.
    
    Grouping only works correctly, if each group contains a complete subtree. This means that for each group there is a node such that the group contains exactly this node and all its descendants.
    
    Default Value:
    The default value is true. Grouping is enabled.
    
    Returns:
    
    true if grouping is supported, false otherwise
    
    See Also:
    
    setGroupingSupportEnabled(boolean)
  - isIntegratedEdgeLabelingEnabled
```
public boolean isIntegratedEdgeLabelingEnabled()
```
    Gets whether or not edge labels are placed by the layout algorithm.
    If this is enabled, the TreeLayout.SubtreeShapes of the subtrees are extended by the edge labels.
    
    The layout algorithm uses the information of PreferredPlacementDescriptor for an edge label to determine the corresponding placement. However, edge labels are always placed at the target side of the edge. The placement along the edge only affects the order of the edge labels at the same edge.
    
    When enabling this property, any previously specified labeling algorithm will be overwritten and when disabling it, any currently specified labeling algorithm will be disabled via property LabelingEnabled. Therefore, it is recommended to only use this convenience property instead of manually changing the mentioned other properties.
    
    Default Value:
    The default value is false. Edge labels are ignored.
    
    Returns:
    
    true if the layout algorithm places edge labels, false otherwise
    
    See Also:
    
    setIntegratedEdgeLabelingEnabled(boolean)
  - isMultiParentAllowed
```
public boolean isMultiParentAllowed()
```
    Gets whether or not multi-parent structures are allowed for this tree layout.
    If multi-parent structures are allowed, the directed input graph may contain structures of multiple nodes that share the same predecessors as well as the same successors. All nodes belonging to such a structure are placed side by side and the incident edges are routed in a bus-style manner.
    As for the different ways in which the INodePlacers route their edges, multi-parent structures only work for some INodePlacer implementations:
    
    DefaultNodePlacer delivers the best results for multi-parent structures. However, routing style RoutingStyle.FORK_AT_ROOT as well as root alignments RootAlignment.LEADING_ON_BUS and RootAlignment.TRAILING_ON_BUS are not supported.
    
    DendrogramNodePlacer supports multi-parent structures.
    
    BusNodePlacer supports multi-parent structures.
    
    LeftRightNodePlacer supports multi-parent structures.
    If the input graph contains groups, all nodes belonging to the same multi-parent structure must be associated with the same group node, i.e., it is not possible to assign these nodes to different group nodes.
    
    Default Value:
    The default value is false. Multi-parent structures are not allowed.
    
    Returns:
    
    true if multi-parent structures are allowed, false otherwise
    
    See Also:
    
    setMultiParentAllowed(boolean)
  - isNodeLabelConsiderationEnabled
```
public boolean isNodeLabelConsiderationEnabled()
```
    Gets whether or not the layout algorithm reserves space for node labels.
    If this feature is enabled, the TreeLayout.SubtreeShape of the nodes will also hold the shapes of its labels.
    
    When enabling this property, any previously specified labeling algorithm will be overwritten and when disabling it, any currently specified labeling algorithm will be disabled via property LabelingEnabled. Therefore, it is recommended to only use this convenience property instead of manually changing the mentioned other properties.
    
    Default Value:
    The default value is false. Node labels are not considered.
    
    Returns:
    
    true if node labels are considered, false otherwise
    
    See Also:
    
    setNodeLabelConsiderationEnabled(boolean)
  - layoutRoot
```
protected TreeLayout.SubtreeShape layoutRoot(Node localRoot)
```
    Calculates the layout for the given root node and its subtrees.
    This method is invoked for each node in the tree exactly once. Thus, children are always handled before their parents. In this manner, the subtrees already have a layout and can be arranged with their parent.
    
    To retrieve the shapes of the subtrees of all children of the local root, this method uses getSubtreeShape(Node).
    
    The method may be overridden to add configuration code.
    
    Parameters:
    
    localRoot - the root of the subtree that whose layout is calculated
    
    Returns:
    
    the combined TreeLayout.SubtreeShape of the local root node and all of its children and connecting edges
  - reverseEdges
```
protected void reverseEdges(EdgeList reversedEdges)
```
    Reverses the direction of given edges.
    This method will be called initially after the directTree() method and finally after the layout has been calculated. It may be overridden to additionally reverse data that depends on the direction of the edges.
    
    Parameters:
    
    reversedEdges - the edges that will be reversed
  - setComponentLayoutEnabled
```
public void setComponentLayoutEnabled(boolean value)
```
    Sets whether or not the ILayoutStage used for arranging the components of the graph is activated.
    
    Overrides:
    
    setComponentLayoutEnabled in class MultiStageLayout
    
    TreeLayout can only handle single components. Disabling ComponentLayout will lead to errors during execution.
    
    Default Value:
    The default value is true. The stage that arranges connected graph components is activated.
    
    Parameters:
    
    value - true if the stage that arranges the graph components is activated, false otherwise
    
    See Also:
    
    MultiStageLayout.isComponentLayoutEnabled(), MultiStageLayout.setComponentLayout(com.yworks.yfiles.layout.ILayoutStage), ComponentLayout
  - setDefaultLeafPlacer
```
public void setDefaultLeafPlacer(INodePlacer value)
```
    Sets the default INodePlacer instance that places the leaf nodes of the tree.
    
    Throws:
    
    IllegalArgumentException - if the default INodePlacer is set to null
    
    Default Value:
    The default value is LeafNodePlacer
    
    Parameters:
    
    value - the default INodePlacer instance
    
    See Also:
    
    setDefaultNodePlacer(INodePlacer), getDefaultLeafPlacer()
  - setDefaultNodePlacer
```
public void setDefaultNodePlacer(INodePlacer value)
```
    Sets the default INodePlacer instance that arranges all subtrees that do not have a specific INodePlacer assigned using a IDataProvider.
    
    Throws:
    
    IllegalArgumentException - if the default INodePlacer is set to null
    
    Default Value:
    The default value is DefaultNodePlacer
    
    Parameters:
    
    value - the default INodePlacer instance
    
    See Also:
    
    NODE_PLACER_DPKEY, getDefaultNodePlacer()
  - setDefaultOutEdgeComparator
```
public void setDefaultOutEdgeComparator(Comparator<Object> value)
```
    Sets the default Comparator instance that sorts the outgoing edges in all subtrees that do not have a specific Comparator assigned using a IDataProvider.
    
    When a Comparator for outgoing edges is null, the order of the edges will be maintained.
    
    Default Value:
    The default value is null. No sorting is executed.
    
    Parameters:
    
    value - the new default instance or null if no specific sorting should be done
    
    See Also:
    
    OUT_EDGE_COMPARATOR_DPKEY, getDefaultOutEdgeComparator()
  - setDefaultPortAssignment
```
public void setDefaultPortAssignment(IPortAssignment value)
```
    Sets the default IPortAssignment instance for all subtrees that do not have a specific IPortAssignment assigned using a IDataProvider.
    
    Throws:
    
    IllegalArgumentException - if the default IPortAssignment is set to null
    
    Default Value:
    The default value is DefaultPortAssignment
    
    Parameters:
    
    value - the default IPortAssignment instance
    
    See Also:
    
    PORT_ASSIGNMENT_DPKEY, getDefaultPortAssignment()
  - setGroupingSupportEnabled
```
public void setGroupingSupportEnabled(boolean value)
```
    Sets whether or not group nodes are handled by the layout algorithm.
    
    If this option is disabled, group nodes will be temporarily hidden and reinserted to enclose their content. This may lead to node overlaps.
    
    Grouping only works correctly, if each group contains a complete subtree. This means that for each group there is a node such that the group contains exactly this node and all its descendants.
    
    Default Value:
    The default value is true. Grouping is enabled.
    
    Parameters:
    
    value - true if grouping is supported, false otherwise
    
    See Also:
    
    isGroupingSupportEnabled()
  - setIntegratedEdgeLabelingEnabled
```
public void setIntegratedEdgeLabelingEnabled(boolean value)
```
    Sets whether or not edge labels are placed by the layout algorithm.
    If this is enabled, the TreeLayout.SubtreeShapes of the subtrees are extended by the edge labels.
    
    The layout algorithm uses the information of PreferredPlacementDescriptor for an edge label to determine the corresponding placement. However, edge labels are always placed at the target side of the edge. The placement along the edge only affects the order of the edge labels at the same edge.
    
    When enabling this property, any previously specified labeling algorithm will be overwritten and when disabling it, any currently specified labeling algorithm will be disabled via property LabelingEnabled. Therefore, it is recommended to only use this convenience property instead of manually changing the mentioned other properties.
    
    Default Value:
    The default value is false. Edge labels are ignored.
    
    Parameters:
    
    value - true if the layout algorithm places edge labels, false otherwise
    
    See Also:
    
    isIntegratedEdgeLabelingEnabled()
  - setMultiParentAllowed
```
public void setMultiParentAllowed(boolean value)
```
    Sets whether or not multi-parent structures are allowed for this tree layout.
    If multi-parent structures are allowed, the directed input graph may contain structures of multiple nodes that share the same predecessors as well as the same successors. All nodes belonging to such a structure are placed side by side and the incident edges are routed in a bus-style manner.
    As for the different ways in which the INodePlacers route their edges, multi-parent structures only work for some INodePlacer implementations:
    
    DefaultNodePlacer delivers the best results for multi-parent structures. However, routing style RoutingStyle.FORK_AT_ROOT as well as root alignments RootAlignment.LEADING_ON_BUS and RootAlignment.TRAILING_ON_BUS are not supported.
    
    DendrogramNodePlacer supports multi-parent structures.
    
    BusNodePlacer supports multi-parent structures.
    
    LeftRightNodePlacer supports multi-parent structures.
    If the input graph contains groups, all nodes belonging to the same multi-parent structure must be associated with the same group node, i.e., it is not possible to assign these nodes to different group nodes.
    
    Default Value:
    The default value is false. Multi-parent structures are not allowed.
    
    Parameters:
    
    value - true if multi-parent structures are allowed, false otherwise
    
    See Also:
    
    isMultiParentAllowed()
  - setNodeLabelConsiderationEnabled
```
public void setNodeLabelConsiderationEnabled(boolean value)
```
    Sets whether or not the layout algorithm reserves space for node labels.
    If this feature is enabled, the TreeLayout.SubtreeShape of the nodes will also hold the shapes of its labels.
    
    When enabling this property, any previously specified labeling algorithm will be overwritten and when disabling it, any currently specified labeling algorithm will be disabled via property LabelingEnabled. Therefore, it is recommended to only use this convenience property instead of manually changing the mentioned other properties.
    
    Default Value:
    The default value is false. Node labels are not considered.
    
    Parameters:
    
    value - true if node labels are considered, false otherwise
    
    See Also:
    
    isNodeLabelConsiderationEnabled()
  - setParallelEdgeRouterEnabled
```
public void setParallelEdgeRouterEnabled(boolean value)
```
    Sets whether or not the ILayoutStage used for routing parallel edges is activated.
    
    Overrides:
    
    setParallelEdgeRouterEnabled in class MultiStageLayout
    
    TreeLayout cannot handle parallel edges. Disabling ParallelEdgeRouter will lead to errors during execution.
    
    Default Value:
    The default value is true. The stage that routes parallel edges is activated.
    
    Parameters:
    
    value - true if the stage responsible for routing parallel edges is activated, false otherwise
    
    See Also:
    
    MultiStageLayout.isParallelEdgeRouterEnabled(), MultiStageLayout.setParallelEdgeRouter(com.yworks.yfiles.layout.ILayoutStage), ParallelEdgeRouter
  - setSelfLoopRouterEnabled
```
public void setSelfLoopRouterEnabled(boolean value)
```
    Sets whether or not the ILayoutStage used for routing self-loops is activated.
    
    Overrides:
    
    setSelfLoopRouterEnabled in class MultiStageLayout
    
    TreeLayout cannot handle self-loops. Disabling SelfLoopRouter will lead to errors during execution.
    
    Default Value:
    The default value is true. The stage that routes self-loops is activated.
    
    Parameters:
    
    value - true if the stage responsible for routing self-loops is activated, false otherwise
    
    See Also:
    
    MultiStageLayout.isSelfLoopRouterEnabled(), MultiStageLayout.setSelfLoopRouter(com.yworks.yfiles.layout.ILayoutStage), SelfLoopRouter

Class TreeLayout

Layout Style

Concept

Features

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class com.yworks.yfiles.layout.MultiStageLayout

Methods inherited from class java.lang.Object

Field Detail

CRITICAL_EDGE_DPKEY

graph

MULTI_PARENT_DESCRIPTOR_DPKEY

NODE_PLACER_DPKEY

OUT_EDGE_COMPARATOR_DPKEY

PORT_ASSIGNMENT_DPKEY

SELECTED_ROOT_DPKEY

Constructor Detail

TreeLayout

Method Detail

applyLayoutCore

createNodeShape

directTree

getDefaultLeafPlacer

getDefaultNodePlacer

getDefaultOutEdgeComparator

getDefaultPortAssignment

getNodePlacer

getOutEdgeComparer

getPortAssignment

getRootsArray

getSourceGroupDataAcceptor

getSourcePortConstraintDataAcceptor

getSubtreeShape

getTargetGroupDataAcceptor

getTargetPortConstraintDataAcceptor

isGroupingSupportEnabled

isIntegratedEdgeLabelingEnabled

isMultiParentAllowed

isNodeLabelConsiderationEnabled

layoutRoot

reverseEdges

setComponentLayoutEnabled

setDefaultLeafPlacer

setDefaultNodePlacer

setDefaultOutEdgeComparator

setDefaultPortAssignment

setGroupingSupportEnabled

setIntegratedEdgeLabelingEnabled

setMultiParentAllowed

setNodeLabelConsiderationEnabled

setParallelEdgeRouterEnabled

setSelfLoopRouterEnabled